America's Small-Bay Industrial Stock Is 43 Years Old — and Almost Nobody Is Building More

The median small-bay industrial building in the United States was built in 1982. That makes the typical building where American small business actually operates — contractors and distributors, yes, but also fabricators, auto shops, HVAC and plumbing outfits, sign makers, caterers, gyms, e-commerce sellers, and hundreds of other business types — 43 years old. Only 7.3% of the small-bay stock has gone up since 2015. Large industrial, by contrast, has a median vintage of 1995 — and 21.5% of it is new.

I want to sit with that gap, because I think it's the most important fact in industrial real estate that almost nobody is talking about.

For five years the whole sector has stared at the same thing: the big-box boom, the giant distribution centers rising along the interstates faster than tenants could fill them. That story is real. But the more interesting fact — the one that reframes the market — is what didn't get built. Underneath the boom, the small buildings that local businesses rent got old and stayed old. The headline is a construction story. The investable truth is a scarcity story.

So we ran the numbers on our own universe. What follows is a SpanVor data study, computed across our national industrial records as of July 10, 2026.

What we mean by "small-bay"

Before the numbers, the definition — because this term gets used loosely. Throughout this study, the small-bay universe means industrial property under 200,000 square feet, and it includes the full family of formats that trade under different names: small bay, shallow bay, light industrial, warehouse, flex office/warehouse, and micro-bay. If it's an industrial building under 200,000 SF, it's in. Large industrial means 200,000 SF and up — the big-box distribution product the last decade's construction boom was built around.

Who occupies small-bay matters just as much as what it is: this is the real estate of American small business at large — not one or two tenant industries, but hundreds of distinct business types, from machine shops to medical suppliers. (That occupier mix is a study of its own, and one we intend to publish.)

The finding, in five numbers

Median small-bay (under 200,000 SF) building was built in 1982 — 43 years old.
Median large industrial (200,000+ SF) building was built in 1995 — a full 13 years newer.
7.3% of small-bay stock has been built since 2015. For large industrial it's 21.5% — roughly three times the rate.
63.8% of small-bay stock predates 1990. Nearly two-thirds of the buildings were up before the fall of the Berlin Wall.
Small-bay construction peaked in the 1980s and collapsed after 2010. The 2010s produced fewer surviving small-bay buildings than any decade since the 1950s.

How old is America's small-bay industrial stock?

Old, and getting older every year that new supply stays thin. In SpanVor's records, the median small-bay industrial building — anything under 200,000 SF — carries a recorded year built of 1982, so the middle building in the country is 43 years old. 63.8% of the stock went up before 1990. Only 9.7% has been built since 2010, and just 7.3% since 2015.

Put plainly: the newest tenth of this market is fifteen-plus years old. When the newest slice of a category is that aged, you are not looking at a market that fresh construction can flood. You're looking at one where the existing buildings — the older, infill, awkward-to-replace ones — quietly become the whole game.

Why is big-box so much newer than small-bay?

Because the boom capital of the last decade went almost entirely into large buildings. The median large-industrial building in our data was built in 1995, and 21.5% of large industrial has gone up since 2015 — about three times the small-bay rate of 7.3%. Same sector, two completely different construction stories.

| Metric | Small-bay (under 200K SF) | Large industrial (200K+ SF) | |---|---|---| | Median year built | 1982 | 1995 | | Median building age | 43 years | Materially younger | | Share built since 2015 | 7.3% | 21.5% |

That's the punchline of the whole study. The big-box boom everyone underwrote for five years was real — it just never reached the small-bay end of the market. Developers built the boxes and skipped the bays.

When did small-bay construction peak?

In the 1980s — and it has never come close since. The table below counts the small-bay buildings still standing by the decade they were built (surviving stock, not historical permits). The shape tells the story better than any single stat: a build-out that crested in the Reagan years, staged a brief comeback in the 2000s, and then fell off a cliff.

| Build decade | Small-bay buildings still standing | |---|---| | 1950s | 46,364 | | 1960s | 62,852 | | 1970s | 88,009 | | 1980s | 116,222 (the peak) | | 1990s | 67,780 | | 2000s | 95,631 | | 2010s | 36,799 | | 2020s (to date) | 23,024 |

Look at the last two rows against the peak. The 2010s delivered 36,799 surviving small-bay buildings — fewer than the 1960s, and less than a third of the 1980s. Construction of the small stuff didn't slow after 2010. It collapsed.

Which states have the oldest small-bay industrial stock?

The oldest stock sits in the legacy industrial states of the Northeast and the coastal West; the newest sits in the Sun Belt. New York's median small-bay building was built in 1953 — the middle building there predates the interstate highway system. California's is 1973, and only 2.1% of California small-bay has been built since 2015, the tightest new-supply rate in the group. Texas, at a median of 1991 with 14.5% post-2015, is the outlier building anything at all.

| State | Median year built (small-bay) | Share built since 2015 | |---|---|---| | Texas | 1991 | 14.5% | | Florida | 1987 | 8.1% | | North Carolina | 1985 | 7.6% | | California | 1973 | 2.1% | | Illinois | 1972 | 2.8% | | Massachusetts | 1970 | 4.8% | | New York | 1953 | 3.6% |

I'd hold this table loosely — a state median is exactly the kind of single number I distrust, and the real story always lives at the submarket and parcel level. But the gradient is hard to miss. Where land is scarcest and industrial zoning is most contested, the stock is oldest and the least new supply is coming. Scarcity compounds where it's already scarce.

Why has small-bay supply frozen?

Because the replacement economics don't pencil, and haven't for years. This is the part I want to be two-handed about, because developers aren't behaving irrationally — they're behaving correctly.

Land. Small-bay wants infill locations near rooftops, and infill land is expensive. The math only works on a large footprint.
Construction cost. Small buildings carry more demising walls, more doors, more utilities, and more tenant improvements per square foot than a bulk box.
Zoning. Industrial land keeps shrinking as cities chase residential and mixed-use tax base, and neighbors resist new industrial.
Financing. Lenders and developers favor larger, simpler, single-tenant deals.

Stack those together and the rational move is to build a 500,000 SF box — or houses — instead of a multi-tenant small-bay park. So the shortage of small-bay isn't a market failure. It's the predictable outcome of everyone doing the sensible thing. Only 23,024 small-bay buildings have gone up in the 2020s so far, and I'd expect that number to stay thin, because none of these constraints is loosening.

What an aging, irreplaceable asset class actually means

Here's the second-level read, and I'll be careful to keep it a read and not a recommendation. On the surface, "43-year-old buildings, no new supply" sounds like a defect — a tired, capital-hungry corner of the market. Flip it over. An asset class with sticky, local demand, a stock that can't be reproduced at today's land and construction costs, and a new-supply pipeline that has collapsed to a trickle isn't a problem to solve. The scarcity is the thesis.

The data suggests something durable: when the newest 7.3% of a category is more than a decade old and replacement cost sits well above the existing basis, time works in favor of whoever already owns the functional, infill stock — and against anyone hoping new construction will bail them out of a bad entry. That's not investment advice, and it's not a promise. It's what the vintage numbers imply. What they don't tell you is which specific 43-year-old building is functional and which is obsolete. That distinction is the entire discipline of this sector, and it's a parcel-level question, not a market-average one.

Frequently asked

How old is the average small-bay industrial building in the U.S.? The median small-bay building (under 200,000 SF) was built in 1982 — 43 years old — per SpanVor's national records as of July 2026. About 63.8% of the stock predates 1990.

Is anyone building new small-bay industrial? Very little. Only 7.3% of small-bay stock has been built since 2015, and just 9.7% since 2010. Construction peaked in the 1980s (116,222 surviving buildings) and collapsed after 2010.

Which state has the oldest small-bay industrial stock? Of the states we studied, New York has the oldest, with a median small-bay building dating to 1953. California is next-oldest at 1973 and has the least new supply (2.1% built since 2015).

Methodology

Figures were computed across SpanVor's national industrial property universe — 1.4 million-plus industrial properties built from primary public records (county assessor rolls, permits, and land records), classified industrial-only. Vintage statistics reflect the 617,000-plus small-bay records and roughly 12,000 large-industrial records that carry a recorded year built. "Small-bay" is defined as the full under-200,000-SF industrial family — small bay, shallow bay, light industrial, warehouse, flex office/warehouse, and micro-bay (see the definition at the top of this study). Figures are current as of July 10, 2026 (Central Time), and describe the SpanVor platform's coverage rather than a complete census of every U.S. building.

Key takeaways

The median U.S. small-bay industrial building was built in 1982 — 43 years old — and 63.8% of the stock predates 1990.
Only 7.3% of small-bay has been built since 2015, versus 21.5% of large industrial — the big-box boom never reached the small-bay end.
Small-bay construction peaked in the 1980s (116,222 surviving buildings) and collapsed after 2010 (36,799 in the 2010s).
New York holds the oldest stock (median 1953); California has the least new supply (2.1% since 2015); Texas is the outlier still building (median 1991, 14.5% since 2015).
The data suggests scarcity is structural, not cyclical — an aging, hard-to-replace stock with sticky local demand.

See it in your market. This study is the national view; the interesting version is your corridor, resolved to parcels — which buildings are old, which are functional, and who owns them. Explore the small-bay universe we map at spanvor.com.

One last thing, since you read this far: the code SpanvorBlog takes 25% off a SpanVor Pro subscription — where the parcel-level data behind posts like this one actually lives.

Written by Jason Probert, Founder of SpanVor — Industrial Property Intelligence.